SONAR (SOund Navigation And Ranging)

When I was in the Navy we had a sonar transducer mounted at the bottom of our ship. I was a SONARMAN by my schooling in the Navy. I listen to sounds in the ocean be it the bottom, whales or ships (1959-1962). The work area was behind closed hatches, small and tight; just enough room to stand and turn around. About the size of mom's bathroom